Hole enlarging and finishing tool



Jan. 19, 1960 J. R. WILLINGHAM Re. 24,769

HOLE ENLARGING AND FINISHING TOOL Original Filed Oct. 18, 1954 INVENTOR.

JO/M/ A. W/ZL/IVGf/IQM ATTOR/VEKS United States Patent Ofiiice Re.24,769 Patented Jan. 19, 1960 Original No. 2,816,464, dated December 17,1957, Serial No. 462,789, October 18, 1954. Application for reissue May21, 1959, Serial No. 814,940

2 Claims. or. 77-58) V Matter enclosed in heavy brackets appears in theoriginal patent but forms no part of this reissue specification; matterprinted in italics indicates the additions made by reissue.

This invention relates to a hole enlarging and work piece side wallfinishing tool for enlarging the apertures and accurately finishing theside walls of work pieces already having a hole roughly formed therein.

This invention relates to a fluid flushed and cooled hole enlarging workpiece side wall finishing tool having chip gathering and flushingcavities in the tip peripheral side wall and a fluid jet for projectinga cooling and flushing stream of fluid against the chips to cool thetool cutting edges and work piece side walls and to dispose of the chipsunder a jet stream influence.

Hole enlarging and finishing tools have been employed heretofore tofacilitate finishing the side walls of a work piece accurately andsmoothly, however, the several devices of the prior art have not provenentirely satisfactory inasmuch as they are not capable of accurately andsmoothly finishing the holes so as to eliminate grinding or separatefinishing after the hole has been axially accurately located, with theresult that the multiple finishing tools of the prior art arecomplicated in design and construction, expensive to manufacture, anddifficult to use, due to the fact that the work piece must be moved frommachine to machine or else multiple tools used to finish the hole.

With the foregoing in view, the primary object of the invention is toprovide a one-operation hole enlarging and finishing tool whichaccurately locates the apertures axially and which also finishes theside walls of the work piece thereby eliminating the necessity of followup machining and grinding.

An object of the invention is to provide a hole finishing tool forenlarging and finishing already partially formed holes in work pieceshaving a central chamber for conducting cooling and flushing fluid tothe tip area of the tool.

An object of the invention is to provide a tip on the tool which has aperipheral cavity longitudinally extending partially over the tip areawith the cavity area surrounded at the sides and top by a greater thannormal radius area so as to contact the side wall of the work pieceunder pressure in sealing relationship relative to the cavity area tocontain the flushing and cooling fluid therein.

An object of the invention is to provide an orifice leading from theshank portion central chamber to the tip cavity whereby fluid underpressure is conducted from the shank chamber to the cavity area.

An object of the invention is to provide a side cutting edge at one sideof the tip cavity wall directly in the path of the projecting coolingfluid so that chips developed and accumulated by the side cutting edgeare flushed away under jet influence so that the cutting edge and thework piece side wall is kept cool by the flow of the fluid therebykeeping chips cleared so that chip scor ing is eliminated.

An object of the invention is to provide end [or bottom] cutting edges[on the same radial plane as the side wall cuuting edges] arranged sothat the cooling and 2 flushing fluid is projected under [with jetinfluence] and against any chips developed by the [bottom] cutting edgesso as to break oil the chips and cool the [bottom] cutting edges and thework piece walls as the work progresses.

An object of the invention is to provide a tool with side and endcutting edges on the same radial plane so that they can very easily besharpened.

These and other objects of the invention will become apparent byreference to the following description of a hole enlarging and workpiece side wall finishing tool embodying the invention taken inconnection with the accompanying drawing:

Fig. 1 is a side elevational view of the tool.

Fig. 2 is a longitudinal axial cross-sectional view of the tip area ofthe tool in conjunction with the work piece. 7

Fig. 3 is a view similar to Fig. 2 taken at thereof; and

Fig. 4 is a cross-sectional view of Fig. 3 taken on the line 44 thereof.1

Referring now to the drawing wherein like numerals refer to like andcorresponding parts throughout the several views, the hole enlarging andwork piece side wall finishing tool disclosed therein to illustrate theinvention comprises a shank portion 10, a collet end 11, a cutting lipend 12, a hollow interior chamber 13 for conducting cooling and flushingfluid from the head of the machine, not shown, to the orifices 14 and 15from thence the fluid is conducted to the peripheral cavity areas 16 and17 which cavities 16 and 17 are surrounded by the raised tip areas 18and 19 respectively for sealing the area of the drill tip and thecavities against return flow of fluid while the tool is operating in thework piece.

More particularly, the inventive hole enlarging and work piece side wallfinishing tool comprises a collet or chuck portion 11 which is shown ofcylindrical shape but which can be of any shape to be receivable andsecurable in the machine head and the shank portion 10 which can be ofany desired length and size. The tip portion 12 can be of any size andlength but it is essention to so form the tip 12 in its side wall areathat it is capable of creating a seal between the work piece side wallaround the area of the cavities 16 and 17 and this accomplished byforming the spaced longitudinal side areas 20 and 21 on a normal radiusand by forming the raised areas 18 and 19 on the radius greater thannormal on both sides and at the top of the cavities 15 and 16respectively. The cavity defining undercut walls 22 and 23 carry cuttingedges 24 and 25 respectively which are adapted to scrape, shave, andburnish the side walls of the work piece after the bottom cutting edges26, 27, 28, and 29 have cut away the side wall areas of the work piecearound the preformed hole in the work piece and it is to be noted thatthe cutting edges 26-28 are formed on the same plane as the cutting edge24 and that the cutting edges 27 and 29 are formed on the same plane asthe cutting edges 25 so that in sharpening the tool, the dead center 30forms a base for placing a center therein for holding the tool steadywhile sharpening.

In operation, the tool is mounted in a machine such as a fluid-fitteddrill-press or milling machine and the collet end 11 is secured theretowith the central chamber 13 connected to the fluid feed on the machineso that cooling and flushing fluid is projected through the chamber 13at a high pressure. The tool is then advanced to the work piece 31 wherethe cutting edges 26 through 29 initially engage the walls of the workpiece to enlarge the hole to the desired size while the following sidewall cutting edges 24 and 25 follow behind and scrape, burnish, andfinish size the hole by removing any shavings, scrapings, high spots, ormalformations due to the lead rate or feed of the tool through the workpiece.

The fluid feeding down through the shank chamber 13, such as seen inFig. 3, is forced through the orifices 14 and 15u'nder high pressureinto the chambers 16 and 17, respectively and it is to be noted that thejet stream and 25 and then past the cutting edges 2629, and since thejet stream of flushing and cooling fluid is immediately adjacent theseedges any chips, shavings, etc. collected by the cutting edges areremoved and subjected to a jet influence wherebythey are broken E and/or flushed out of the cavities 16 and 17 to the preformed hole 32 in thework piece to disposal.

This jet stream of fluid not only cools the work piece side walls andthe tool cutting edges but also is adapted to break off chips and flushout shavings and grindings so that the cutting area is always in cleancondition eliminating chip jamming and scoring and it is to be furthernoted that since the cooling effect of the jet stream is extremelyeificient, the hot chips are immediately cooled and broken oif andflushed out through the preformed hole 32 thereby keeping the workingarea of the drill completely clean at all times.

Relative to the direction of flow, it is to be noted that no backchannelling of the fluid can possibly occur due to the fact that theraised side wall areas 18 and 19 interspaced between the normal sidewall areas 20 and 21 ride against the side wall of the work piece at apressed relationship so that the fluid is completely sealed within thecavity at the top and sides and so that the fluid must flow past theside wall and out through the previously preformed hole 32 in the workpiece. It is to be understood that a sufiicient amount of lubricantfluid can feed back in the spaces 34 and 35 but due to the fact'that nopressure can possibly exist in these spaces there is no possibility ofoil squirting up in the direction opposite the drill feed.

The raised areas 18 and 19 have the additional factor of allowing thedrill or tool to be firmly fixed in thehole Without binding due to thefact that the normal areas 20 and 21 of the drill furnish sufficientrelief to the tool in the hole. In other words, it has been found thatan extremely accurate hole can bedrilled by the use of the inventivedevice having raised areas over the normal diameter due to the fact thatthese raised areas ride on the side walls as a bearing and do not bindin the hole due to the fact that the normal areas interspaced betweenthe raised areas' furnish sufficient relief against friction to enablethe tool to be easily turned in the hole.

The inventive tool with the features described constitutes a compact,durable, simple, and highly efficient combined hole enlarging andfinishing tool which operates extremely easily in the hole and which canvery easily be removed from the hole upon completion of the finishingoperation whereby it saves much time, tooling, and

machinery by eliminating the heretofore multiple use of tools.

Although but a single embodiment of the invention has been shown anddescribed in detail, it is obvious that many changes may be made in thesize, shape, detail, and arrangements of the variouselements of theinvention within thescope of the appended claims.

emitting therefrom is directed downwardly in the cavities 16 and 17 in ajet stream past the cutting edges 24 What is claimed is:

1. A hole enlarging or. side Wall finishing tool comprising a shankportion relatively smaller in diameter than the hole to be bored toeliminate side wall friction having a longitudinal chamber forconducting flushing and cooling fluid therethrough, a cutting tipportion on said shank portion having at least one-longitudinallyextending peripheral cavity in the side wall thereof and an orificeleading from the shank internal chamber to said tip cavityfor conveyingflushing and cooling fluid to said tip portion in the area of saidcavity; said tip portion having raised peripheral side areas on eitherside of said cavity and a raised peripheral top area across the top ofsaid tip cavity interconnecting with said raised side areas; said raisedareas being disposed on a diameter equal to the hole to be bored andadapted to sealab ly engage the internal side wall of a workpiece toprovide a bearing surface and to prevent back channelling of flushingand cooling fluid from said tip cavity to eliminate chips jamming and todirect the entire flow of fluid past the-cutting area andchip'developing area of-the tool to flush chips away from the tooland tocoolthe cutting edges.

2. A hole enlarging and finishing tool comprising a shank portionrelatively smaller in diameter than the hole after enlarging andfinishing with said tool to eliminate side wall friction, said shankportion having a longitudinal chamber for conducting flushing andcooling fluid therethrough, a cutting tip portion on said shank portionhaving a plurality of cutting edges extending transversely of theterminal end of said-tip portion and a plurality of longitudinallyextending peripheral cavities in the side wall thereof corresponding tosaid cutting edges, each cavity having a side wall which extendslongitudinally of said tip portion, each cutting edge being disposed atthe end of the sidewall of the cavity corresponding to said cuttingedge, said tip portion including a plurality of orifices leading fromthe shank internal chamber to said cavities for conveying flushing andcooling fluid to said cavities in a direction from said shank portiontoward the terminal end of said tip portion so that fluid from saidorifices is directed longitudinally of said cavity walls so that itflows across the leading sides of said cutting edges, said tip portionhaving raised peripheral side areas on either side of each of saidcavities, said raised areas being disposed on a diameter substantiallyequal to the hole to be bored andadapted to en gage the internal sidewall of aworkpiece to provide a bearing surface to eliminate chipsjamming and to direct the flow of fluid past the cuttingedge andchip-developing area of the tool to flush chips away from zhetool and tocool the cutting edges.

References Cited in the file of this patent or the original patentUNITED STATES PATENTS 995,572 Rowe June 20, 1911 1,002,451 Rowe Sept. 5,1911 1,323,278 Hoagland Dec. 2, 1919 2,320,333 Pierle May 25, 19432,391,396 Denison Dec. 25, 1945 2,610,529 Atkinson Sept. 16, 1952

